One of the key discoveries in exoplanet research over the past decade is the abundance of small planets in our Milky Way. Despite their high numbers, our understanding of their atmospheres remains... Show moreOne of the key discoveries in exoplanet research over the past decade is the abundance of small planets in our Milky Way. Despite their high numbers, our understanding of their atmospheres remains limited, and it is unknown if they possess atmospheres at all. Predicting the presence of an atmosphere on small planets is challenging due to factors like atmospheric escape and volcanism. Reliable determination requires direct study of thermal emission, reflected light, or transmission spectrum. With the launch of the JWST in late 2021, we gained unprecedented access to detailed observations of rocky exoplanets, enabling the search for atmospheres composed of carbon dioxide, oxygen, and nitrogen on temperate rocky worlds. My thesis summarizes my work on atmospheric characterization of small, rocky exoplanets using space-based telescopes such as Spitzer, Hubble, and JWST. I have studied a wide temperature range, from lava worlds with atmospheres of outgassed rock vapor at over 2000 Kelvin, to terrestrial planets with temperatures around 400 Kelvin, similar to our inner solar system. I characterized the surfaces and atmospheres of exoplanets like K2-141 b and TRAPPIST-1 c to ultimately learn about their surfaces and the conditions under which rocky planets can retain atmospheres. Show less
